1. Filed of the Invention
The present invention relates to switch devices and particularly to a switch device to be turned on or off by the connecting operation of a connecting member which has an electronic circuit, etc.
2. Description of the Related Art
Japanese patent application Kokoku No. 23879/96 discloses a switch device of this type. This device has a contact frame for reading IC cards and comprises a flat frame made of an insulative material so as to provide a window section, and a plurality of contact elements and a pair of switch terminals provided on the flat frame. The contact elements and the switch terminals have connection sections projecting from the frame and contact sections for making spring contact with the corresponding circuit traces of a card. The switch terminals have a fixed contact and a movable contact supported at one end by the frame, with the other end free. The other end of the movable contact is pressed by the inserted card and flexed away from the fixed contact of the other terminal, thus breaking the contact.
For easy manufacturing, the switch terminals are made by stamping a metal sheet and bending the end of a movable contact in a semi-cylindrical form so that both the switch terminals make contact with each other in a line.
The above switch device, however, suffers from low reliability in contact between the switch terminals. If the fixed contact has a completely flat contacting surface and is completely parallel to the contact surface of the semi-cylindrical movable contact, they make a perfect line contact. However, there is always a manufacturing difference although it is within the range of tolerance and it is very difficult to make a line contact but a point contact or contacts. Especially, when the above error makes an angular contact between them, it is almost impossible to make a line contact.
If dirt or dust adheres to the contact, it is not unusual to make poor contact.